I’m not a plumber, but to find real plumbers to give advice, I highly suggest the Terry Love plumbing forums- even if you only search through posts, it has real plumbers that explain what’s up to code and which region’s code.

I recently put in a water softener and needed to add a stand pipe in my basement for it’s drain- the forums got me up and running and gave me an idea of some of the plumbing basics that might be in play here. I’m assuming this is a laundry machine below the actual drain pipe, with a sump pump that’s running up to that p trap.

To me this looks off, because I can’t tell if it has backflow prevention and how it would handle a sewage backup if one happened, without allowing contact to the water supply though the hose and machine. If that’s all dealt with in the sump pump, perhaps a non -issue. Also laundry drains are now meant to go into 2" pipe to handle the amount of flow from HE units- I can’t tell from the pic how big that pipe is.

You might want to look into how the building inspection process works where you live, and if they offer protection in the case of a contractor doing work that does not pass code- some places force them to rip it out and fix it right on their own dime, until the inspector is satisfied.